XML : Configuration format with support for referencing other values

I have been searching for a format which have a functionality similar to:

  [foo]  bar=942    [baz]  qux=@foo.bar/2    

Of course, this is what I have in mind for such a format in INI style.

I am particularly interested in finding a Human-readable/editable format, but it is not a must.

Have you heard of such a format? Is there a general workaround for this?

Thanks